Optical system with reflective baffles

摘要

Baffles (34) in infrared telescope (10) extend circumferentially around tube (12) of the telescope. Each of the baffles (34) has a concave, rearwardly facing curved surface (36) and a frontwardly facing planar surface (38). Baffles (34) extend from the interior wall of tube (12) in an acute angle with the optical axis (20) of the telescope, relative to front end (14) of the tube (12). This acute angle becomes greater for the baffles (34) toward rear end (16) of the telescope (10). Incoming off axis rays (44) are reflected by the planar surface (38) of the baffles (34) against the curved surface (36) of a forward adjacent baffle (34) and are reflected back and forth between adjacent surfaces (38) and (36) a number of times before being reflected back as rays (46) out of the front end of the telescope (10). Other off axis rays (40) are directly reflected as rays (42) by the planar surfaces (38) of the baffles (34).